#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<windows.h>

#define High 20
#define Width 30 

int moveDirection;
int canvas[High][Width]={0};

void gotoxy(int x,int y)
{
	HANDLE handle=GetStdHandle(STD_OUTPUT_HANDLE);
	COORD pos;
	pos.X=x;
	pos.Y=y;
	SetConsoleCursorPosition(handle,pos);
} 

void moveSnakeByDirection()
{
	int i,j;
	for (i=0;i<High-1;i++)
	for (j=0;j<Width-1;j++)
	if (canvas[i][j]>0)
	canvas[i][j]++;
	
	int oldTail_i,oldTail_j,oldHead_i,oldHead_j;
	int max=0;
	for (i=0;i<High-1;i++)
		for (j=0;j<Width-1;j++)
		if (canvas[i][j]>0)
		{
			if (max<canvas[i][j])
			{
				max=canvas[i][j];
				oldTail_i=i;
				oldTail_j=j;
			}
			if (canvas[i][j]==2)
			{
				oldTail_i=i;
				oldTail_j=j;
			}
		}
	canvas[oldTail_i][oldTail_j]=0;
	if (moveDirection==1)
	canvas[oldHead_i-1][oldHead_j]=1;
	if (moveDirection==2)
	canvas[oldHead_i+1][oldHead_j]=1;
	if (moveDirection==3)
	canvas[oldHead_i][oldHead_j-1]=1;
	if (moveDirection==4)
	canvas[oldHead_i][oldHead_j+1]=1;
}

void startup()
{
	int i,j;
	for (i=0;i<High;i++)
	{
		canvas[i][0]=-1;
		canvas[i][Width-1]=-1;
	}
	for (j=0;j<Width;j++)
	{
		canvas[0][j]=-1;
		canvas[High-1][j]=-1;
	}
	canvas[High/2][Width/2]=1;
	for (i=1;i<=4;i++)
	canvas[High/2][Width/2-i]=i+1;
	moveDirection=4;
}

void show()
{
	gotoxy(0,0);
	int i,j;
	for (i=0;i<High;i++)
	{
		for (j=0;j<Width;j++)
		{
			if (canvas[i][j]==0)
			printf (" ");
			else if (canvas[i][j]==-1)
			printf ("#");
			else if (canvas[i][j]==1)
			printf ("@");
			else if (canvas[i][j]>1)
			printf ("*");
		}
		printf ("\n");
	}

}

void updateWithoutInput()
{
	moveSnakeByDirection();
}
void updateWithInput()
{
}
int main()
{
	startup();
	while (1)
	{
		show();
		updateWithoutInput();
		updateWithInput();
	}
	return 0;
}
